This project is part of a preliminary investigation to estimate which types of intersections are best suited for two major road junctions on a new by-pass road in the capital area in Iceland. This investigation is based on enquiries made by the Icelandic Road Administration to evaluate the different types of intersections on the by-pass road in the road junctions at Vífilsstaðavegur road and Arnarnesvegur road.
Based on Icelandic standards for road and intersections design, several scenarios are designed for these road junctions. For creating and simulating scenarios the
microsimulation program VISSIM is used.
First the road network is split in two parts and these investigated individually to estimate the best solution for each one. Nine scenarios with at-grade intersections are simulated for the two parts of the divided network. Then a single combination is chosen for simulation of a combined road network, which is compared with a scenario with grade separated interchanges in both road junctions.
Based on the simulations performed in this project, using grade separated interchanges is recommended to obtain a solution that can effectively manage the future traffic flow on the roads that form the road network in this project. If choosing to use at-grade intersections, a 4-way intersection with traffic lights should be chosen for the road junction between Arnarnesvegurroad, Fífuhvammsvegur road and the By-pass road. And a 3-way intersection with traffic lights should be used in the road junction between the By-pass road and Vífilsstaðavegur road. This combination offers the best handling of traffic obtained with at-grade intersections.
Investigating the differences in priority rules in dual-lane roundabouts in Iceland compared with Danish rules showed little difference between the two in managing traffic.
Investigations show that the use of shunts can be considered for increasing capacity in roundabouts on high capacity roads and should be investigated for the individual intersection as an enhancement.